Optic disc, imaging

In the computer industry, new read/write optical discs, capable of storing over 250 megabytes, utilize a thin coating consisting of a germanium, teUurium, and antimony compound (see Imaging TECHNOLOGY). 

Optical coherence tomography uses reflected light in a manner analogous to the use of sound waves in ultrasonography to create computerized cross-sectional images of the retina and optic disc, and also gives quantitative information about the peripapillary retinal nerve fiber layer thickness. 

ISO (2002). ISO 18925 2002 Imaging materials - Optical disc media - Storage practices. International Organization for Standardization. 

Fig. 10 Images of dual gold hemispheres produced via disconnection (taken from ref. 57). (A,B) SEM images of the dual gold hemisphere junction electrode. (C) Optical mieroscopy image of the platinum double disc electrode before gold electro-deposition (platinum wire diameter 98 pm, gap between electrodes before gold 45 pm). (D) Optical microscopy image of the two gold hemispheres after disconnection.

The resolution or "resolving power" of a light microscope is usually specified as the minimum distance between two lines or points in the imaged object, at which they will be perceived as separated by the observer. The Rayleigh criterion [42] is extensively used in optical microscopy for determining the resolution of light microscopes. It imposes a resolution limit. The criterion is satisfied, when the centre of the Airy disc for the first object occurs at the first minimum of the Airy disc of the second. This minimum distance r can then be calculated by Equation (3). 

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